Barclays boosted its Brent crude oil futures price forecast to around $100 per barrel on Saturday, up from $80 on Friday, after the United States and Israel bombed several sites in Iran.
"Oil markets might have to face their worst fears on Monday. As things stand right now, we think Brent could hit $100 (per barrel), as the market grapples with the threat of a potential supply disruption amid a spiraling security situation in the Middle East," the bank said in a report.
The United States and Israel attacked Iran on Saturday, targeting its top leaders and calling for the overthrow of its government, while Iran responded with missiles fired at Israel and neighboring Gulf countries.
Oil prices rose about 2% on Friday, with traders bracing for supply disruptions as nuclear talks between the US and Iran had yet to reach an agreement.
Brent settled at $72.48 a barrel.
About a fifth of the oil consumed globally passes through the Strait of Hormuz between Oman and Iran, making any disruptions in the area a major risk to global oil supplies.